[13.3] `aspire update` shouldn't re-download if there are no changes.

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the bug

If you run `aspire update --self --channel staging` twice in a row, I'd expect the second attempt to be a no op (as you have the latest version).

Instead it redownloads the current version a second time.

### Expected Behavior

The second `aspire update --self --channel staging` should be a no-op.

### Steps To Reproduce

1. `aspire update --self --channel staging`
2. `aspire update --self --channel staging` again

### Exceptions (if any)

_No response_

### Aspire doctor output

_No response_

### Anything else?

13.3.0+ee860bda2a0c813a9a07b26aa988ae7c279d5562